辽河油田蕴藏着丰富的地热资源,利用废弃油井实现地热资源开发利用能够带来巨大的社会经济效益和环境效益,但利用现有的改井方式改造地热井出水量偏低、伴有出砂现象,不能满足对矿区地热的开发利用.为此,对径向钻孔、射孔 + 压裂防砂技术 2 种改井方式进行了简要介绍,并分别选择废弃油井 JX1 井、JX2 井进行了地热井改井试验,试验表明,在热储层不足的地区利用地热资源时,采用径向钻孔技术改井可以提高单位厚度含水层的产水量,可有效改善现有改井方式存在的地热井出水量偏低问题,在沟通地层增大地层泄流面积方面更具优势.射孔改井的地热井进行压裂填砂可提高防砂效果.针对同时伴有出水量低、出砂 2 个问题的井,建议尝试采用径向钻孔+ 压裂防砂技术联合改井,预期可以大幅度提高出水量、降低出砂量,满足改井要求.
When shale gas reservoir is developed by horizontal wells,due to casing eccentricity and irregular diameter,the displacement efficiency of oil-based drilling fluid is usually low. Some oil-based drilling fluid is mixed into cement slurry,which affects the performance of cement slurry. In order to improve the anti-pollution ability of shale gas cementing cement slurry,the surfactant(AFSG-1) was prepared by mixing non-ionic surfactant and anionic surfactant in the laboratory. The research on improving the anti-pollution performance of shale gas well cementing cement slurry by AFSG-1 was carried out with the field oil-based drilling fluid and cementing cement slurry as the research object. The results showed that the addition of oil-based drilling fluid in the field would seriously affect the fluidity,thickening time and mud-mixed water and debris properties of cement slurry.The greater the proportion of oil-based drilling fluid,the more serious the pollution was. With the increasing amount of AFSG-1 in cement slurry,the anti-pollution ability of cement slurry was gradually enhanced. When the mass fraction of AFSG-1 in cement slurry was 2%,and then 20% oil-based drilling fluid was added,the fluidity,thickening time and cement stone properties of the slurry were significantly improved compared with those without surfactant. In addition, the anti-pollution performance improvement effect of AFSG-1 on oil-based drilling fluid of cement slurry was significantly better than that of other commonly used surfactants. AFSG-1 could effectively improve the ability of shale gas cement slurry to resist the pollution of oil-based drilling fluid,improve the cementing quality and ensure the cementing safety.
径向水平钻孔技术能够利用原井筒在地层不同深度、方向上,直接钻出多个辐射状径向孔眼,明显扩大施工井泄流面积,助力油气田增产增注.该技术以高压流体为钻孔动力,且涉及到打开地层,井喷现象具有较大威胁.本文简要介绍了径向水平钻孔技术原理、特点、应用等情况,着重对该技术现场施工井控措施进行了探讨,总结了各种井控工具及使用方法,为该技术的进一步研究和发展提供了借鉴.
现有水力钻孔技术虽然弥补了传统火药射孔穿透距离短、有压实效应等不足,但施工时需要油管或连续管配合,作业周期长、成本高,而且仅依靠地面泵压信号难以直接准确监测施工进程.针对这一问题,进行了井壁深穿透电控钻孔技术研究.优选直流电机代替高压水泵作为施工的能量来源;采用电缆悬吊方式代替油管或连续管传送钻孔工具,通过电缆传输电能和发送控制命令控制钻孔作业;研制实时监测系统,以及时准确地监测地层钻进过程,形成了井壁深穿透电控钻孔系统.地面试验和现场试验证明,该技术可钻入地层2.00 m以上,形成直径20.0~30.0 mm的孔道,其监测系统通过识别和记录井下霍尔传感器在地层钻进时产生的脉冲电信号,可及时准确地计算出实际钻孔长度.研究结果表明,井壁深穿透电控钻孔技术采用电缆传送,高效、快速、成本低,很好地弥补了传统火药射孔的不足,为沟通改造近井地层提供了一种新方法;同时,该技术的监测系统可在施工时对钻进长度等参数实时监测,解决了现有水力钻孔技术无法监测施工进程的问题.
由于传统液体流量计在低渗透油田小流量检测中存在灵敏度低、重复性差、分辨率低等缺点,小流量的精准检测已成为国内低渗透油田亟待解决的技术难题.针对此问题,设计了一种基于DSP芯片的热式液体流量计,该系统基于恒定温差和热扩散原理,当液体流经集成了加热电阻的测速传感器时,利用加热反馈电路维持测速传感器和环境温度差值恒定不变,通过测量加热电阻上的电压来计算液体流量,使用增量式PID算法进行温度的动态控制,实现流量快速、稳定的测量.通过室内实验,分析了环境温度对测量结果的影响,验证了仪器的工作性能.实验结果表明,该流量计对0~5 m3/d的小流量检测具有较高的灵敏度,其相对误差小于1%,可解决低流量精准测量问题.
伊通地堑二号断层是依通地堑一条重要的断层,分隔鹿乡断陷及岔路河断陷,断层两侧发育有梁家和五星两个重要的含油气构造带.本文通过高质量的三维地震资料的精细解释,研究了二号断层的几何学特征,分析了其空间变化特征、动态演化特征及其与油气运聚关系,认为二号断层不仅横切伊通地堑,而且具有控盆作用,向东与岔路河断陷的东部边界断层连为一体,其演化经历了早期张扭作用及晚期压扭作用,对两侧构造带发育具有明显控制作用,同时认为该断层是一条重要的油源断层,对油气成藏有重要控制作用.